We're unable to sign you in at this time. Please try again in a few minutes.
We were able to sign you in, but your subscription(s) could not be found. Please try again in a few minutes.
There may be a problem with your account. Please contact the AMA Service Center to resolve this issue.
Contact the AMA Service Center:
Telephone: 1 (800) 262-2350 or 1 (312) 670-7827  *   Email: subscriptions@jamanetwork.com
Error Message ......
Article |

The Thinker's Sign

Herbert J. Rothenberg, MD
JAMA. 1963;184(11):902-903. doi:10.1001/jama.1963.03700240094024.
Text Size: A A A
Published online


To the Editor:  —Repeated pressure on and friction of the epidermis results in a characteristic hyperkeratotic plaque known as a callus. Production of these lesions requires chronic intermittent stimulation, such as might be a feature of certain occupations—hence, the well-known lesions on the shoulders of hod-carriers, the hands of mechanics, the lips of trumpeters, and the thumbs of leather buffers. There seems to be less appreciation of the fact that certain chronic disease states might result in the widespread adoption of characteristic postures, satisfying the mechanical requirements for callus formation, and consequently resulting in lesions as specific for the disease state as the lesions named are for the corresponding occupations. An example of just such an occurrence is herein described.Bilateral discrete calluses are frequently observed in the suprapatellar areas of patients suffering from chronic pulmonary disease with advanced respiratory insufficiency. The characteristic posture instinctively assumed by patients attempting to


Sign in

Purchase Options

• Buy this article
• Subscribe to the journal
• Rent this article ?

First Page Preview

View Large
First page PDF preview




Also Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
Please click the checkbox indicating that you have read the full article in order to submit your answers.
Your answers have been saved for later.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.


Some tools below are only available to our subscribers or users with an online account.

0 Citations

Sign in

Purchase Options

• Buy this article
• Subscribe to the journal
• Rent this article ?

Related Content

Customize your page view by dragging & repositioning the boxes below.